It is necessary in casting devices of the mentioned type to move the melt without turbulence onto a conveyor belt. With strip thicknesses of between 5 and 10 mm and casting performances of up to 20 t/h, only metallostatic levels of a few millimeters, for example, are needed for the necessary supply pressure. In order to achieve this, DE-PS 3 810 302, for example, describes a vacuum system. DE-PS 4 132 189 uses a pipette principle.
The basic purpose of the invention is to provide a casting device of the mentioned type such that underpressure is not at all needed.
The purpose is attained according to the invention in such a manner that the melt distributor includes a distributor base which terminates in a surface that extends essentially tangential to a surface of the conveyor belt supported on guide rollers and at a center-point angle .alpha. in front of the apex point (12:00 o'clock position) of the front guide roller (viewed in moving direction of the conveyor belt) that is in the range of 5.degree. to 20.degree.. The front guide roller is cooled at least in the area thereof defined by the respective center-point angle .alpha.. The center-point angle .alpha. is thereby calculated counterclockwise starting at the 12:00 o'clock position.
Thus the distributor in the casting device of the invention is joined closely with its base to the radius of the guide roller such that there practically does not exist any difference in height between the distributor base and the conveyor-belt plane.
It is known in casting devices for carrying out the so-called melt-drag method that molten metal (compare, for example, EP-OS 0 174 765) is cast onto a mold disc approximately in the 9:00 o'clock position; compared with this melt feeding at 9:00 o'clock, the feeding principle of the invention disclosed therein has the advantage that only a very thin, first shell solidifies in arched form (to the radius of the guide roller). Because of the short arch path, the small dimension and the high temperature, this region of the melt is again straightened during the further transport by the guide roller. Thus no or only such minute microcracks, which can be removed during the subsequent milling, are created. Furthermore, since in the casting device of the invention disclosed therein the melt level can be freely adjusted, the disadvantage of the casting device used for the so-called melt-drag method is avoided, namely, a condition where an uneven cooling over the strip width would cause the strip thickness to vary accordingly.
According to a preferred embodiment of the invention, the range for the center-point angle .alpha. is 5.degree. to 10.degree..
In order to guarantee a constant melt supply during the start-up phase, the distributor base is inclined at an angle .beta.=1.degree. to 3.degree. with respect to the conveyor-belt plane E.
Since the material of the part of the distributor base which extends to a location adjacent the front guide roller must have a finite thickness, the thickness at the casting-out or terminal edge of the distributor base is preferably D=1 to 5 mm.
To guide the solidified molten metal, laterally spaced boundary walls are integrated into the boundary walls of the metal distributor, wherein in particular the underside of the distributor base rests, in the area of these lateral boundaries, on the conveyor belt.
According to a, particular embodiment of the invention, the melt distributor is connectively arranged at the outlet of a furnace. In order to avoid an adjusting of the heavy holding furnace, it may, however, be advantageous in many cases to adjust the melt distributor independently of the holding furnace, namely to arrange same independently of the furnace.
In particular for the further moderation of the melt flow and to avoid slag inclusions in the surface of the strip, a smoothing bar movable in the conveyor-belt plane or perpendicularly thereto is associated with the melt distributor and according to the invention.